Bird fluOverview

Bird flu, or avian flu, is an infectious type of influenza that spreads among birds. In rare cases, it can affect humans.

There are many different strains of bird flu virus, most of which don't infect humans. However, 4 particular strains have caused serious concern in recent years:

H5N1 (since 1997)

H7N9 (since 2013)

H5N6 (since 2014)

H5N8 (since 2016)

Although these viruses don't infect people easily and aren't usually transmitted from human to human, several people have been infected around the world, leading to a number of deaths.

Bird flu affects many species of birds, including chickens, ducks, turkeys and geese. It can be passed between commercial, wild and pet birds. Birds don't always get sick from infection, so seemingly healthy birds may still pose a risk to people who come into contact with them.

Bird flu in the UK

No humans have been infected with H5N1, H7N9, H5N6 or H5N8 bird flu in the UK, although plans are in place to manage any suspected cases.

In January 2018, a number of cases of H5N6 bird flu were identified in wild birds in 2 separate locations in the UK (South Dorset and Warwickshire). This led to the Department for Environment, Food and Rural Affairs (Defra) introducing a Bird Flu Prevention Zone in England.

During 2016/17, there were several outbreaks of H5N8 bird flu in poultry flocks and wild birds in the UK and Europe. Since then, there have been further outbreaks of H5N8 across the Middle East, Africa and Asia. Worldwide, there have been no human cases of H5N8.

The last reported case of H5N1 in birds in the UK was in early 2008. H7N9 hasn't been detected in wild birds or poultry in the UK.

Signs and symptoms

Diarrhoea, vomiting, stomach pain, chest pain, and bleeding from the nose and gums have also been reported as early symptoms in some people.

These symptoms can come on suddenly. The time from infection to the start of symptoms (incubation period) is usually 3 to 5 days, although in some cases it can be up to 7 days.

Within days of symptoms appearing, potentially fatal complications such as pneumonia, acute respiratory distress syndrome and multiple organ failure may develop. Prompt treatment with antiviral medication may help prevent complications and reduce the risk of death.

Treatment for bird flu

People with suspected symptoms of bird flu will be advised to stay at home or be cared for in hospital in isolation from other patients.

Antiviral medication

In the UK, certain antiviral medications have been stockpiled for use in the event of a flu outbreak. These medications work by stopping the virus multiplying in your body.

Oseltamivir (Tamiflu) and zanamivir (Relenza) help reduce the severity of the condition, prevent complications and improve the chances of survival.

For regular flu, these medications are most effective if given within 48 hours of symptoms developing, but it's not clear if this is the case for bird flu. They should be given as soon as possible to people suspected or proven to be infected, sometimes even if it's more than 48 hours after symptoms started. This decision would be made by the doctor prescribing the medication.

These medications may also be given as a preventative measure to people who could have been exposed to bird flu viruses – for example, other household members, healthcare workers or people who've been in close contact with infected birds, depending on the circumstances.

Treating complications

Complications such as bacterial pneumonia may develop in some people and can be treated with regular antibiotics.

People who are severely affected may need to be given extra oxygen to help them breathe – for example, through a ventilator (a machine that assists with breathing).

When to seek medical advice

Contact your GP or call NHS 111 immediately if you experience symptoms and have visited an area affected by bird flu in the past 2 weeks.

An initial assessment can be made over the phone, at a GP surgery, at home or in a side room at a hospital.

Bird flu is diagnosed based on your symptoms and the likelihood that you've been exposed to an infected bird. You should tell the doctor if you have:

recently travelled to an area affected by bird flu and if you've been close (within a metre) to live or dead domestic fowl or wild birds, including those at bird markets

had close contact (touching or speaking distance) with anyone who has a severe respiratory illness

had contact with anyone who died unexpectedly and was from an area that had an outbreak

If bird flu is suspected, the following tests will be carried out to establish the diagnosis:

Another possible source of bird flu can be live markets, where birds are sold in crowded and sometimes unsanitary conditions. Avoid visiting these markets if you're travelling in countries that have had an outbreak of bird flu.

Bird flu isn't transmitted through cooked food, so cooked poultry and eggs are safe to eat in areas that have experienced outbreaks of bird flu.

Preventing bird flu

There are a number of things you can do to reduce your risk when visiting areas where outbreaks have been reported:

avoid visiting live animal markets and poultry farms

avoid contact with surfaces that are contaminated with bird droppings

don't pick up or touch birds (dead or alive)

don't eat or handle undercooked or raw poultry, egg or duck dishes

don't bring any live poultry products back to the UK, including feathers

Human cases

The World Health Organization (WHO) confirmed that by January 2018, 860 people had been infected with the H5N1 virus worldwide and 454 had died. Indonesia, Egypt and Vietnam experienced most cases and fatalities.

Reports of people being infected with the H7N9 virus across mainland China began in March 2013. By January 2018, there had been 1,565 confirmed cases and 612 deaths. Most cases were among middle-aged and elderly men. A small number of cases were reported in travellers from Hong Kong, Taiwan, Macao, Malaysia and Canada.

Since 2014, there have been 19 human cases of infection with H5N6, all reported in mainland China. This strain is different to the H5N6 seen in Europe – the latter hasn't been associated with any human cases.

There have been some reports of limited human-to-human transmission of H5N1 and H7N9 viruses, usually as a result of very close contact between family members or in hospital settings. The H5N6 virus seen in China has so far not been transmitted from person to person.

People who've had bird flu generally developed the virus after coming into close and prolonged contact with infected birds. Millions of birds have been killed during outbreaks to prevent the disease spreading and being passed on to people.